Summary
Robert Downey Jr.is coming back to the MCU as a villain. TheMarvel Cinematic Universeis bringing back its biggest star. However, Iron Man actor RDJ will not play Tony Stark but rather be the main foe in thenext Avengers movie. The decision seems to phase out Kang the Conqueror and the Council of Kangs, as Downey will give life to one of the biggest Marvel villains of all time.
Marvel Studios has announced atSan Diego Comic-Con, whereScreen Rantis in attendance, thatRobert Downey Jr. will play Doctor Doom inAvengers: Doomsday. Downey appeared on stage in full Doctor Doom costume before revealing himself (via@rob_keyes/Twitter).

The movie was originally calledAvengers: The Kang Dynasty, but withKang the Conqueror actor Jonathan Majors fired from the MCU, Marvel has decided to pivot and focus the next Avengers movie on Doctor Doom. Downey will now appear in multipleupcoming MCU films.
Robert Downey Jr’s Rumored MCU Return Role Is Marvel’s Best Kang Replacement
Avengers 5 will reportedly leave Kang the Conqueror behind, and Robert Downey Jr.’s rumored MCU twist return could lead to the best Kang replacement.
Why Robert Downey Jr. Is Doctor Doom In Avengers: Doomsday
Downey Makes His MCU Return In Shocking Manner
After Marvel’s Kang the Conqueror plans fizzled out, the only way to get the MCU back on track was to go bigger. Marvel has been making some changes to how it operates, with the studio now set to focus on its biggest franchises and characters in the coming years. As such, introducing Doctor Doom is the perfect move to set up the final chapter of the Multiverse Saga, and Downey makes for an interesting choice for the role.
While there might be some confusion due to Downey’s long time as Iron Man in the MCU, the actor actually has a history with the Marvel villain he will now play. That is becauseDowney auditioned to portray Doctor Doom in the 2000’s Fantastic Four movies. With that past connection and the actor coming off an Oscar-winning villain role inOppenheimer, RDJ can easily make Doctor Doom a major force in the MCU that requires every hero to work together.

As for how the MCU could explain its Tony Stark actor playing Doctor Doom, the answer is fairly simple. Downey’s Doom is coming into the Multiverse Saga, and so he could come from another universe, trying to rule over the multiverse, and that leads to a battle with the Avengers and other heroes. Marvel’s Fantastic Four reboot is heavily rumored to take place in another universe, soRobert Downey Jr.’s Doctor Doom could come from there and cross over into Earth-616 inAvengers: Doomsday.
Avengers: Doomsday
Avengers: Doomsday will bring Earth’s Mightiest Heroes together for the first time in the Infinity Saga. Not having appeared since Avengers: Endgame in the MCU Phase 3, the wide range of heroes must find a way to come together to defend Earth once more.